Step 4: Configure USB Type-A Connector plug

Step 5: Future Enhancements

I would like to add the following enhancements in the future. 1. A better circuit box to protect the circuit. 2. Add a switch 3. Add a female U...

Even though, there are plenty of "Dynamo Bike Light" instructions on this site, I thought I would share mines. The great news, there are NO resistors in my circuit. It has a fixed 5 volt output, so you can ride as fast as you want without worrying about burning out the LEDs. Also, since this has a 5v output, you can hook up virtually any high-powered (CREE/Luxeon) LED flashlights (typically rated 4.5v - 8v). I use this circuit to power a CREE RC-G4 Flashlight , which i bought from DealExtreme for $17. (It's very bright, but I will most likely upgrade to SSC P7 900-Lumen LED Flash Light, not bad deal for $38.67).

I will also hook up a USB connector plug to charge my BlackBerry Phone and Ipod. Most USB devices are rated 5v , so with this circuit like this, you will never need to deal with a solar charger to charge your phone, GPS, ipod, recharable batteries, or to power any standard USB device.

Please refer to Step 1, Step 2, Step 3 & Step 4 for further details..

FYI: This is a work in progress, and I will update my instructions as my project progresses. Please bear with me given my hectic schedule and feel free to contact me if you have questions regarding where to get the parts or accessories. And don't forget to leave feedback and suggestions.

I am working on a similar idea , the only difference is I have very low speed of cycling, around 15 rpm. So please suggest an appropriate dynamo and what changes do i need to make in the circuit to get a constant output of 5V at low speeds. please help!!

Another question/idea; wouldn't it be possible to put a little stack of rechargeable batteries (4x1.5V) between the rectifier bridge and the regulator in order to store some energy and feeding the regulator when not cycling ?? Therefore having some power feeding the lights when not moving.

thanks for the instructions, I have one question though. why not drill two holes in the side of the flashlight body for the wires to exit and integrate the rear on/off/mode switch of the flashlight into the wiring?

Also check out the new crop of "on/off" hub dynos. In the off position the magnets are disengaged and there is no drag, much like a bottle dyno. I have provided links to three of them below.

A very nice idea. I recommend you take a look at switched regulators (dealsextreme have quite a few, and they are not expensive at all). They do not loose energy to heat like a regular linear regulator (like the one you built). Sometimes they are called buck-boost (or something like that). Check them out!

Thank you. Yes. I am not 100% done yet. I got a bit too excited and published it soon. This circuit could benefit any touring or commuting cyclist, especially when winter is around the corner and it will be dark outside :)

I will break it down to more steps with more explanation. I am not an expert on electronics by any means, but this circuit seems to work well (took me less than an hour to build). so far, I have not burned any LEDs yet (I rode 2 hrs non-stop). I have yet to stress test it, and hook up a USB device to charge. I will update the instructions as time progresses. Hopefully, it will hold up to my expectations.